Armature-core insulation



, 1 619,415 March 1927' A. B. GOMORY ARMATURE PURE INSULATION OriginalFiled Feb. 3, 1923 gvmmmtor and particularly Patented Mar. 1, 192 7.

UNITED STATES ALBEB'1 IB. GOMOBY, OF A NDERSON, INDIANA, ASSIGNOR, ."BYMES'NE ASSIGNMENTS, TO DELCO-REHY CORPORATION, OF DAYTON, OHIO, ACORPORATION OF DELAWARE.

MATURE-CORE INSULATION.

Original application filed February 8, 1928, serial No. 616,842. Dividedand this application filed September 26, 1924.

This invention relates to the manufacture of armatures for dynamoelectric machines to armatures having open slotted cores.

This application is a divlsion of my copending application Serial No.616,842, file February 3, 1923.

It is an object of this invention to improve the manner of insulatingthe armature core in order that during the winding operation theliability of injuring the insulation of the core or the. insulation onthe armature conductors will be minimized.

A further object of the invention 1s to provide suitable apparatus forcarry ng out the "process described herein.

1 Other and'further objects of the present invention will be a parentfrom the following description, re erence being bad to the accompan'yindrawings, wherein a preferred em o'rfiment of the present invention isclearly shown.

'In the drawings:

Figs. 1 and 2 are perspective views of core slot insulating strips;

Fig. 3 is aplan view of an assembling tool for facilitating theapplication of the insulating strips to the armature core;

' Fig. 4 is a perspective view of an armature core showing the processof insertlng the slot insulation;

Fig. 5 is a perspective view of an armature core provided with slotinsulation;

Fig. 6 is a fragmentary sectional view of the armature on an enlargedscale with windin s in the slots; and

ig. 7 is a view similar to Fig. 6 and shows a further step in theinsulating process. g

The armature shown in Fig. 4 includes a shaft carrying a laminated corehaving iron laminations 34 and nonconducting end laminations 36.Adjacent the laminations 36, the shaft 30 is provided with -insulatingtubes (one of which is indicated at 37 in Fig. 5) formed preferably bywrapping around the shaft several turns of insulating paper and pastingdown the free end.

Before winding the wire upon the armature core it is necessary that thecore slots be provided with linings of thin insulating material such asinsulating paper or other fibrous nuaterial. Especially where thearmature coils are to be wound upon the Serial No. 740,057.

core by a winding machine. It is desirable that the outer periphery ofthe core teeth as well as the'stems of the core teeth which define thewinding slots, be covered With insulating paper in order that theinsulating wrapping of the wire will not come in contact with any metalpart and be in-- jured. It is also desirable that the insulating' liningmaterial be arranged so that there will be no edges of it which arelocated in the path of movement of the wire as it is Wound into thearmature slots. Heretofore it has been the practice to apply acontinuous strip of sheet insulating material against the armature corein a manner such that each core tooth will be entirely covered by asmooth insulating covering. When the windings are applied to a corewhich has been insulated in this manner the windings tend to press thecore insulating material against the stems of the core teeth whichdefine the winding slots. Because the paper cannot stretch to anyappreciable degree it will be torn in the elfort to push it against thesides of the core teeth. The present invention overcomes this difiicultyby providing a novel method of manufacturing an armature which will nowbe described.

The next step is to line the core slots with bifurcated or U-shapedstrips 40 shown in Fig. 1 and with bifurcated or V-shaped strips 41shown in Fig. 2. Each slot is provided first with a V strip 41 as shownin Fig. 5, and then the U strips 40 are placed around the core teethwith the base portion 42 adjacent the periphery of the tooth and thebranch portions 43 and 44 adjacent the stem of the tooth and locatedoutside the V strips 41. To facilitate assembling the U strips upon thecore there is provided an assembling tool 45 having a hub 46 which isadapted to embrace the shaft 30 and the insulating tube 37 thereon, anda plurality of fingers 47 of triangular cross section which extendradially from the hub 46. The widest space (indicated at 48 in Fig. 3)between the bases of the fingers 47 is substantially as wide as thespace between adjacent core teeth at the periphery of the core. Thestrips 40 and 41 are preferably of stiff insulating paper and theportions 43 and 44 of the strip 40 are formed so that they have atendency to spring together. The tool 45 is assembled upon the armatureas shown in loo 1 the branc Fig. 4 after the V strips 41 have been assembled in position, and each strip 40 1s assembled by moving one endthereof ad acent a finger 47 so that the upper edge 49 of the timer actsas a wedge to spread apart h portions 43 and 44 of the strip 40, and tocause these portions to enter readily into adjacent armature slots. Aseach strip 40 is assembled, the branch portions 43 and 44 will springback into closer relation to each other and will tend to bear againstthe V strips 41. There is sufiicient resiliency in the branches of theinsulating strips 41 to cause them to spread out and cling to the sidesof the slot. The branch portions of the strip 40 tend to spring togetherand cling to the V strips 41. In this manner the core slot insulationstrips are held prior to the winding operation in properly assembledposition simply by means of frictional engagement with the core. Thearmature is now ready for the winding rocess.

The winding of the core is performed preferably by means of ap aratusand according to a process disclose in my copending applications SerialNo. 616,842 and Serial No. 740,058. The winding of the wires into thecore slots causes the V strips 41 to be drawn toward the center of thecore while the branches 43 and 44 of the U strips 40 are pressed towardthe core teeth. If the slot lining is made of a continuous strip, thereis a tendency for the slot lining to tear because there is a tendency tostretch it as the windings are pressed down into the armature slots. Inthe present method of slot insulation, the branches of the strips 40 and41 may slide relative to one another so that the lining material may bepacked against the sides of the slots without tearing. The strips 41 and42 are long enough so that their ends come flush with the outer faces ofthe core insulating disc 36.

After the winding process the armature strips 40 are out along the edgesA and B so that the base )ortion 42 of each strip 40 can be discarded.The outer edges of the branch portions 43 and 44 are packed down againstthe armature conductors as indicated at 43' and 44 and these edges andthe wires are held in position by means of strips of stiff paper shownin Fig. 7. These strips are located between the armature core teeth andthe folded down lining portions 43 and 44. A subsequent operation ofimpregnating the armature with an insulating varnish and baking willcause the lining members to adhere to one another and to the core teeth,and the tendency of the conductors to move out radially due tocentrifugal force causes the strips 90 to be clamped even more firmlyagainst the core teeth to prevent the portions 43 and 44 assuming aradial position.-

While the process and apparatus herein shown and described constitute apreferred 1. The process of making an armature, I

having a core provided with open slots which are defined by spaced coreteeth having ste n portions which are narrower than the portions of theteeth adjacent their outer peripheries, which includes lacing withineach slot an insulating mem er which lines the bottom of the slot andportions onl of the sides of the slot, lacin over eaci tooth aninsulating mem r w ich covers the tooth outer periphery and is providedwith portions extending within the slot and overlapping those ortions ofthe first insulating member w ich line the sides of the slot, in windingwire into each slot to cause the bottom of the first lining member to bedrawn against the bottom of the slot and the overlapping portions ofboth lining members to be pressed against the sides of the slot, saidoverlapping portions sliding the one relative to the other in order toconform to the core teeth sides, and then removing those portions of thesecond mentioned insulating members which cover the teeth outerperipheries.

2. The process of making an armature, having a core rovided with openslots which are defined by spaced core teeth having stem portions whichare-narrower than the portions of the teeth adjacent their outerperipheries, which includes placing within each slot an insulatingmember which lines the bottom of the slot and portions only of the sidesof the slot, placing over each tooth an insulating member which coversthe tooth outer periphery and is provided with portions extending withinthe slot and overlapping those portions of the first insulating memberwhich line the sides of the slot, in winding wire into each slot tocause the bottom of the first lining member to be drawn against thebottom of the slot and the overlapplng portions of both lining membersto be pressed against the sides of the slot, said overlapping portionssliding the one relative to the other in order to conform to the coreteeth sides, then removing those portions of the second mentionedinsulating inembers which cover the teeth outer peripheries, folding theremaining portions of the second mentioned insulating members againstthe windings in each slot and insertno a ing a retaining insulatingmember in each slot between the folded insulating parts and portionswhich are narrower than the portions of the teeth adjacent-their outerperi heries, which includes lining each slot with a bifurcatedinsulating member having a part for lining the bottom of the slot andbranches for lining rtions only of the sides of the slot, and limng thesides of each slot with the branch portions of bifurcated insulatingmembers which have yoke portions coveringthe outer peripheries of thecore-teeth and branch portions extending within the slots, the branchportions of the lining members overlapping within the slots, in windingwire 1nto each slot to cause the bottom of the first lining member tobe' i drawn against the bottom of the slot and the overlapping ortionsof both lining members to be pressed against the sides of the slot, 7said overlanping portions sliding the one relative to the other in;order to conform to the core teeth sides, and then removing thoseportions of the second mentioned insulating members which cover theteeth outer peripheries.

' In testimony whereof I hereto aflix my 26' signature. 3

ALBERT n. GOMORY.

